mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-26 14:33:02 +02:00
3315e168ee
Zero is used by BlockFrequencyInfo as a special "don't know" value. It also causes a sink for frequencies as you can't ever get off a zero frequency with more multiplies. This recovers a 10% regression on MultiSource/Benchmarks/7zip. A zero frequency was propagated into an inner loop causing excessive spilling. PR16402. llvm-svn: 184584
74 lines
2.1 KiB
C++
74 lines
2.1 KiB
C++
//===-------- BlockFrequency.h - Block Frequency Wrapper --------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements Block Frequency class.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SUPPORT_BLOCKFREQUENCY_H
|
|
#define LLVM_SUPPORT_BLOCKFREQUENCY_H
|
|
|
|
#include "llvm/Support/DataTypes.h"
|
|
|
|
namespace llvm {
|
|
|
|
class raw_ostream;
|
|
class BranchProbability;
|
|
|
|
// This class represents Block Frequency as a 64-bit value.
|
|
class BlockFrequency {
|
|
|
|
uint64_t Frequency;
|
|
static const int64_t ENTRY_FREQ = 1024;
|
|
|
|
public:
|
|
BlockFrequency(uint64_t Freq = 0) : Frequency(Freq) { }
|
|
|
|
/// \brief Returns the frequency of the entry block of the function.
|
|
static uint64_t getEntryFrequency() { return ENTRY_FREQ; }
|
|
|
|
/// \brief Returns the frequency as a fixpoint number scaled by the entry
|
|
/// frequency.
|
|
uint64_t getFrequency() const { return Frequency; }
|
|
|
|
/// \brief Multiplies with a branch probability. The computation will never
|
|
/// overflow. If the result is equal to zero but the input wasn't this method
|
|
/// will return a frequency of one.
|
|
BlockFrequency &operator*=(const BranchProbability &Prob);
|
|
const BlockFrequency operator*(const BranchProbability &Prob) const;
|
|
|
|
/// \brief Adds another block frequency using saturating arithmetic.
|
|
BlockFrequency &operator+=(const BlockFrequency &Freq);
|
|
const BlockFrequency operator+(const BlockFrequency &Freq) const;
|
|
|
|
bool operator<(const BlockFrequency &RHS) const {
|
|
return Frequency < RHS.Frequency;
|
|
}
|
|
|
|
bool operator<=(const BlockFrequency &RHS) const {
|
|
return Frequency <= RHS.Frequency;
|
|
}
|
|
|
|
bool operator>(const BlockFrequency &RHS) const {
|
|
return Frequency > RHS.Frequency;
|
|
}
|
|
|
|
bool operator>=(const BlockFrequency &RHS) const {
|
|
return Frequency >= RHS.Frequency;
|
|
}
|
|
|
|
void print(raw_ostream &OS) const;
|
|
};
|
|
|
|
raw_ostream &operator<<(raw_ostream &OS, const BlockFrequency &Freq);
|
|
|
|
}
|
|
|
|
#endif
|